Film cassette

ABSTRACT

In a film cassette, a spool core is supported for rotation in an unwinding direction to thrust a leader section of a film roll coiled about the spool core to the exterior of the cassette and in a winding direction to return the leader to the interior of the cassette. A pair of flanges are arranged in spaced relation along the spool core to radially confine the leader. The flanges are adapted to be flexed apart to permit the leader to readily escape the confinement of the flanges when the spool core is rotated in the unwinding direction. According to the invention, the leader has respective edge portions for flexing the flanges apart in succession when the spool core is rotated in the unwinding direction, whereby the leader can more easily overcome any resistance the flanges may present to movement of the leader outwardly of the flanges.

CROSS-REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly assigned copending applications Ser. No.07/320,440, entitled FILM CASSETTE, and filed Mar. 8, 1989 in the nameof John J. Niedospial; Ser. No. 07/415,750, entitled FILM CASSETTE, andfiled Sept. 27, 1989 in the name of John J. Niedospial; and Ser. No.07/464,264 entitled FILM CASSETTE, and filed Jan. 9, 1990 in the namesof Edward H. Dowling, et al.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates generally to the field of photography, andParticularly to a film cassette containing roll film. More specifically,the invention relates to a film cassette that is capable ofautomatically advancing a non-protruding film leader to the exterior ofthe cassette shell responsive to unwinding rotation of a film spoolwithin the shell. 2. Description of the Prior Art

In conventional 35 mm film manufacturers' cassettes, such asmanufactured by Eastman Kodak Co. and Fuji Photo Film Co. Ltd., thefilmstrip is wound on a flanged spool which is rotatably supportedwithin a cylindrical shell. A leading or forward-most section of thefilmstrip approximately 21/3 inches long, commonly referred to as a"film leader", normally protrudes from a light-trapped slit or mouth ofthe cassette shell. One end of the spool has a short axial extensionwhich projects from the shell, enabling the spool to be turned by hand.If the spool is initially rotated in an unwinding direction, the filmroll inside the shell will tend to expand radially since the inner endof the filmstrip is attached to the spool, and the fogged leader sectionprotruding from the slit will remain stationary. The film roll canexpand radially until a firm non-slipping relation is establishedbetween its outermost convolution and the inner curved wall of theshell. Once this non-slipping relation exists, there is a binding effectbetween the film roll and the shell which prevents further rotation ofthe spool in the unwinding direction. Thus, rotation of the spool in theunwinding direction cannot serve to advance the filmstrip out of theshell, and it is necessary in the typical 35 mm camera to engage theprotruding leader section to draw the filmstrip out of the shell.

A 35 mm film cassette has been proposed which, unlike conventional filmcassettes, can be operated to automatically advance a film leader out ofthe cassette shell by rotating the film spool in the unwindingdirection. The film leader originally is located entirely inside thecassette shell. Specifically, in U.S. Pat. No. 4,423,943, granted Jan.3, 1984, there is disclosed a film cassette wherein the outermostconvolution of the film roll wound on the film spool is radiallyconstrained by respective circumferential lips of two axially spacedflanges of the spool to prevent the outermost convolution fromcontacting an inner curved wall of the cassette shell. The trailing endof the filmstrip is secured to the film spool, and the forward orleading end of the filmstrip is slightly tapered purportedly to allow itto freely extend from between the circumferential lips and rest againstthe shell wall at a location inwardly of a non-light tight filmpassageway to the outside of the cassette shell. During initialunwinding rotation of the film spool, the leading end of the filmstripis advanced along the shell wall until it reaches an inner entrance tothe film passageway. Then, it is advanced into and through the filmpassageway to the outside of the cassette shell. The passageway has awidth that is less than the width of the filmstrip, thus resulting inthe filmstrip being transversely bowed as it is uncoiled from the filmspool, and thereby facilitating movement of the film edges under thecircumferential lips of the flanges. However, severe transverse bowingof the filmstrip in order to move its longitudinal edges under thecircumferential lips of the flanges may damage the filmstrip.

Like the type of film cassette disclosed in U.S. Pat. No. 4,423,923,commonly assigned U.S. Pat. Nos. 4,834,306 granted May 30, 1989,4,848,693, granted July 18, 1989, and 4,860,037, granted Aug. 22, 1989,each disclose a film cassette that is capable of automatically advancinga non-protruding film leader to the outside of the cassette shell inresponse to rotation of the film spool in the unwinding direction.Specifically, there is disclosed a film cassette wherein a film roll iswound on a spool between a pair of coaxially spaced, independentlyrotatable flanges. The two flanges have respective circumferentialannular lips which prevent the outermost convolution of the film roll,including its leading end, from clock-springing into contact with theinterior wall of the cassette shell. When the spool is initially rotatedin the unwinding direction, the flanges may momentarily remainstationary and the film roll, since its inner end is secured to thespool, tends to expand radially to ensure a firm non-slipping relationbetween the outermost convolution and the annular lips. Once thenon-slipping relation exists, continued rotation of the spool willsimilarly rotate the flanges. This allows stationary internal spreadersto deflect successive portions of the annular lips to an axial dimensionexceeding the film width, in turn allowing the leading end andsuccessive sections of the film roll to be freed from the radialconfinement of the annular lips and to be advanced into and through alight tight film passageway to the outside of the cassette shell. Astripper-guide located adjacent an inner entrance to the film passagewaydiverts the leading end of the film roll into the passageway by beingreceived between the leading end and the next-inward convolution of thefilm roll responsive to unwinding rotation of the spool.

The Cross-Referenced Applications

Cross-referenced applications Ser. Nos. 07/320,440, 07/415,750, and07/464,264 each disclose a film cassette wherein a film roll whoseoutermost convolution is a film leader is coiled about a spool rotatablewithin the cassette shell, a pair of flexible independently rotatableflanges are coaxially arranged on the spool to radially confine the filmleader within respective skirted peripheries of the flanges to preventthe leader from substantially contacting an interior wall of thecassette shell, and a film stripper-guide projecting from the interiorwall is received between a leading end of the film leader and thenext-inward convolution of the film roll to free the leader from theflanges and guide the leader through a light tight film passageway tothe exterior of the cassette shell responsive to rotation of the spoolin a film unwinding direction. Specifically, the stripper-guide freesthe film leader from the flexible flanges by inducing the leader tosimultaneously flex the two flanges farther apart at their skirtedperipheries during unwinding rotation of the spool. Moreover, the filmleader and at least one of the flanges include mutual engagement meansfor maintaining the leading end of the leader spaced at least a minimumradial distance from the next-inward convolution of the film rollsufficient to locate the leading end within range of the stripper-guide,to ensure that the leading end will be advanced over the stripper-guideresponsive to rotation of the spool in the film unwinding direction.

SUMMARY OF THE INVENTION

It has been found that by allowing the film leader to flex therespective flanges farther apart at their skirted peripheries one afterthe other, rather than simultaneously as in the cross-referencedapplications, when the spool is rotated in the unwinding direction, theleader can more easily overcome any resistance the flanges may presentto movement of the leader outwardly of the skirted peripheries.

Thus, the invention may be summarized as follows:

A film cassette comprising a spool core supported for rotation in anunwinding direction to thrust a leader section of a film roll coiledabout the spool core to the exterior of the cassette and in a windingdirection to return the leader to the interior of the cassette, and apair of flanges arranged in spaced relation along the spool core toradially confine the leader and adapted to be flexed apart to permit theleader to readily escape the confinement of the flanges when the spoolcore is rotated in the unwinding direction, is characterized in that theleader has respective edge portions for flexing the flanges apart insuccession, i.e. one after the other, when the spool core is rotated inthe unwinding direction, whereby the leader can more easily overcome anyresistance the flanges may present to movement of the leader outwardlyof the flanges.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of a film cassette according to apreferred embodiment of the invention;

FIG. 2 is an elevation view of the film cassette, illustrating thecassette shell open to reveal a film roll coiled about a film spool;

FIG. 3 is an end view partly in section of the cassette shell, the filmroll and the film spool, illustrating the manner in which the film rollis originally stored on the film spool;

FIGS. 4, 5, 6 and 7 are end views similar to FIG. 3, illustrating themanner in which the film roll is unwound from the film spool;

FIGS. 8 and 9 are elevation views of the film roll and the film spool,illustrating the manner in which the film roll is originally stored onthe film spool;

FIGS. 10 and 11 are elevation views similar to FIGS. 8 and 9,illustrating the manner in which the film roll is unwound from the filmspool;

FIG. 12 is an exploded perspective view of the film spool without thefilm roll; and

FIG. 13 is an elevation view partly in section of the film roll and thefilm spool, illustrating the manner in which one of a pair of filmconfining flanges of the spool may be fixed to the spool for concurrentrotation with the spool.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The invention is disclosed as being embodied preferably in a 35mm filmcassette. Because the features of this type of film cassette aregenerally well known, the description which follows is directed inparticular to elements forming part of or cooperating directly with thedisclosed embodiment. It is to be understood, however, that otherelements not specifically shown or described may take various formsknown to persons of ordinary skill in the art.

Referring now to the drawings, FIGS. 1, 2 and 12 depict an improved 35mm film cassette 1 comprising a light-tight cassette shell 3 and a filmspool 5 which is rotatable about an axis X in film unwinding and windingdirections U and W within the cassette shell. The cassette shell 3consists of two shell halves 7 and 9 which are mated along respectivegrooved and stepped edge portions 11 and 13. The mated halves 7 and 9define upper and lower aligned circular openings 15 and 17 forrelatively shorter and longer opposite open-end pieces 19 and 21 of aspool core or hub 23, and they define a narrow relatively-straight filmpassageway 25 to the exterior of the cassette shell 3. The longer andshorter open-end pieces 19 and 21 of the spool core 23 each include anannular peripheral groove 27 which mates with a corresponding edgeportion 29 of the respective openings 15 and 17 in the cassette shell 3to rotatably support the film spool 5 for rotation about the axis X inthe film unwinding and winding directions U and W. A known black velvetor plush material 31 lines the interior of the film passageway 25 toprevent ambient light from entering the film passageway.

A roll 33 of 35 mm filmstrip F is coiled about the spool core 23 to formsuccessive film convolutions. As shown in FIG. 3, the film roll 33includes an outermost convolution which comprises a film leader 35having a leading or forward end 37, and it includes a next-inwardconvolution 39 coiled behind the outermost convolution. The inner ortrailing end of an innermost convolution 40 of the film roll 33 issecured to the spool core 23 using known attachment means, not shown.See FIG. 13.

A pair of upper and lower identical, very thin, flexible filmconstraining flanges 41 and 43 are coaxially spaced along the spool core23 as shown in FIGS. 1, 2, 8, 12 and 13. The two flanges 41 and 43comprise respective integral disks 45 and 47 and respective integralannular lips or skirts 49 and 51 which circumferentially extend from thedisks. The two disks 45 and 47 cover opposite substantially flat sidesof the film roll 33 which are defined by corresponding oppositelongitudinal edges 53 and 55 of each successive convolution of the filmroll, and they have respective central holes 56 through which the spoolcore 23 coaxially extends to permit rotation of the spool core relativeto the flanges 41 and 43. See FIG. 12. Respective circumferentialrecesses 57 are provided in the spool core 23 for supporting the flanges41 and 43 at their disks 45 and 47 to permit the flanges to beindependently rotated about the axis X. The two recesses 57 aresufficiently spaced from one another along the spool core 23 to maintainrespective inner faces 45' and 47' of the disks 45 and 47 slightlyspaced from the longitudinal edges 53 and 55 of each successiveconvolution of the film roll 33. See FIG. 13. The annular lips 49 and 51overlap the film leader (outermost convolution) 35 of the film roll 33radially outwardly of the longitudinal edges 53 and 55 of the leader toradially confine the leader to thus prevent it from radially expandingor clock-springing into substantial contact with an interior curved wall58 of the cassette shell 3. An elongate lip-receiving notch or cut-out59 is cut in the film leader (outermost convolution) 35 along itslongitudinal edge 55, relatively close to its leading end 37, to receivea peripheral section 51' of the annular lip 51. This allows a relativelyshort edge portion 61 of the leader's longitudinal edge 55 whichconnects the leading end 37 and the notch 59 to overlap the annular lip51 radially outwardly to thus maintain the leading end spaced a radialdistance D from the next-inward convolution 39 of the film roll 33. SeeFIGS. 4 and 9. The leading end 37 has a forward edge 63 inclined fromthe leader's longitudinal edge 53 to the leader's longitudinal edge 55to form a forward-most tip or tab 65 of the film leader 35 which, likethe edge portion 61, overlaps the annular lip 51 radially outwardly. SeeFIGS. 1, 2, 8 and 9.

The two flanges 41 and 43 have a plurality of concentric arcuate slots66 cut in their respective disks 45 and 47 to longitudinally extend inthe film unwinding and film winding directions U and W. Engagement meansin the form of respective hook-like members 67, located on the short andlonger open-end pieces 19 and 21 of the spool core 23, are normallylocated in the concentric slots 66 for movement along the slots intoengagement with the flanges 41 and 43 responsive to rotation of thespool core relative to the flanges in the unwinding direction U and formovement along the slots out of engagement with the flanges responsiveto rotation of the spool core relative to the flanges in the windingdirection W. See FIGS. 12 and 13. Preferably, each of the hook-likemembers 67 has an end face 67' that is beveled to ease the hook-likemember out of one of the concentric slots 66 responsive to rotation ofthe spool core 23 relative to the flanges 41 and 43 in the windingdirection W, in the possible event the spool core is rotated relative tothe flanges far enough in the winding direction to back the hook-likemember out of the slot.

A film stripper-guide 68 projecting from the interior wall 58 of thecassette half 7 is positioned immediately inward of the inner entranceto the film passageway 25 to be received between the leading end 37 ofthe film leader (outermost convolution) 35 and the next-inwardconvolution 39, close to the forward-most tip 65 of the leader, to pickup the leading end and guide it into the film passageway responsive torotation of the spool core 23 in the unwinding direction U. See FIGS. 1and 4-7. The leading end 37 will be advanced over the stripper-guide 68and into the film passageway 25, rather than between the stripper-guideand the next-inward convolution 39, because it is spaced the radialdistance D from the latter convolution. Thus, as shown in FIG. 4, theleading end 37 will be located within range of the stripper-guide 68 dueto such spacing D from the next-inward convolution 39.

When the leading end 37 of the film leader (outermost convolution) 35 isinitially advanced over the stripper-guide 68 responsive to rotation ofthe spool core 23 in the unwinding direction U, an inclined edge portion53' of the leader's longitudinal edge 53 starts to locally flex theflange 41 farther apart from the flange 43. See FIG. 10. Since only theflange 41 is flexed at this time, it operates to maintain the notch 59in the leader's longitudinal edge 55 at the lip section 51' of theannular lip 51. The notch 59, in turn, allows the film leader 35 to moveoutwardly of the flange 43 without that flange having to be flexed. SeeFIG. 10. The notch 59 is sufficiently spaced from the leader's forwardedge 63 to allow at least the forward-most tip 65 to be thrustsubstantially to the exterior of the cassette shell 3 before the flange43 needs to be flexed as in FIG. 11. Then, with continued rotation ofthe spool core 23 in the unwinding direction U, an inclined edge portion55' of the leader's longitudinal edge 55 starts to locally flex theflange 43 farther apart from the flange 41 to allow the notch 59 toseparate from the lip section 51'. Following this, successivelongitudinal sections of the film leader 35 exit from between theflanges 41 and 43 to the exterior of the cassette shell 3. See FIG. 11.The flexing of each of the flanges 41 and 43 occurs because the filmwidth WF between the leader's longitudinal edges 53 and 55 is slightlygreater than the axial spacing A_(S) between the annular lips 49 and 51.See FIG. 11. Moreover, successive convolutions of the film roll 33 havea resistance to transverse bowing that is greater than the resistance ofthe flanges 41 and 43 to be locally flexed. A pair of flat curvedbearing members 69 extend from the interior wall 58 of the cassetteshell 3 to lie flatly against successive arcuate portions of the twodisks 45 and 47 as the flanges 41 and 43 are locally flexed axially awayfrom one another, to thereby assure return of the flexed portions of theflanges to their normal original non-flexed condition. See FIGS. 1 and2.

A film flattening member 71 projects from the interior wall 58 of thecassette half 9 in the vicinity of the inner entrance to the filmpassageway 25 and the stripper-guide 68 to support successivelongitudinal sections of the film leader 35, beginning with its leadingend 37, substantially flat as those sections are freed from the flange41, to facilitate movement of the leading end into the passageway. SeeFIGS. 6 and 7. The light-trapping plush 31 within the film passageway 25is elevated along the passageway slightly beyond a longitudinal centerline L of the passageway. The film flattening member 71 as shown in FIG.3 projects almost to the center line L in order to support successivesections of the film leader 35 substantially flat at the center line.See FIGS. 6 and 7. Preferably, a substantially planar film-supportingface 73 of the flattening member 71 is spaced 0.005"-0.030" short of thecenter line L, and extends widthwise of the film passageway 25 as shownin FIG. 1.

Optionally, a slot 75 is cut in the film leader (outermost convolution)35 substantially proximate its leading end 37. A tooth 77 fixed to theinterior wall 58 of the cassette half 7 has a free pointed end 79 whichis positioned to be received in the slot 75 to thus engage the filmleader (outermost convolution) 35, when the film spool 5 is rotated inthe winding direction W as shown in FIG. 3, and to exit the slot to thusdisengage the leader, when the film spool is rotated in the unwindingdirection U as shown in FIG. 4. The engagement of the film leader(outermost convolution) 35 and the tooth 77 responsive to rotation ofthe film spool 5 in the winding direction W prevents the leading end 37of the leader from coming to rest between the stripper-guide 67 and thenext-inward convolution 39.

OPERATION

When the spool core 23 is initially rotated in the film unwindingdirection U, the two flanges 41 and 43 momentarily tend to remainstationary and the film roll 33, since its inner end is attached to thespool core, will expand radially or clock-spring to force the filmleader (outermost convolution) 35 firmly against the annular lips 49 and51 of the flanges. Generally however, before the film roll 33 can beexpanded radially to the extent a non-slipping relation would be createdbetween the film leader (outermost convolution) 35 and the annular lips49 and 51 as in commonly assigned U.S. Pat. Nos. 4,834,406 and4,848,693, the hook-like members 67 will have moved along the respectiveslots 66 into engagement with the two flanges 41 and 43 to fix theflanges to the spool core. Then, further rotation of the spool core 23will similarly rotate the flanges 41 and 43. As a result, the leadingend 37 of the film leader (outermost convolution) 35 will be advancedover the stripper-guide 68, first causing the leader's inclined edgeportion 53 to locally flex the flange 41 and then causing the leader'sinclined edge portion 55' to locally flex the flange 43 as shown inFIGS. 10 and 11. This first allows the notch 59 to separate from the lipsection 51', and then it allows successive longitudinal sections of thefilm leader 35 to exit from between the flanges 41 and 43. Since thestripper-guide 68 initially picks up the leading end 37 of the filmleader 35 close to its forward-most tip 65, the forward edge 63 of theleading end might initially be supported along a narrow ridge 81 formingone end of the interior wall 58 of the cassette half 7. However, theleading end 37 will tend to back away from the ridge 81 and move againstthe film-supporting face 73 of the flattening member 71 as shown in FIG.6.

If the spool core 23 is rotated in the film winding direction W aftersome length of the filmstrip F has been advanced from the cassette shell3, the spool core is free to rotate relative to the two flanges 41 and43 because the hook-like members 67 can move along the respective slots66 out of engagement with the flanges. This permits the flanges 41 and43 to be independently rotated in the winding direction W, though at aslower speed than the spool core 23 is rotated in that direction. Eachof the hook-like members 67 may back out of one of the slots 66 and intothe next slot during continued rotation of the spool core 23 in thewinding direction W. At the same time, the filmstrip F will be rewoundonto the spool core 23 between the flanges 41 and 43. The spool core 23is rotated in the winding direction W substantially until the slot 75 inthe film leader (outermost convolution) 35 receives the free end 79 ofthe tooth 77 to thus engage the film leader to the tooth. As shown inFIGS. 10 and 11, the film leader 35 has respective edge portions 53" and55" of its longitudinal edges 53 and 55 that are located one forward ofthe other, ahead of the inclined edge portions 53' and 55', that arerelieved to allow the flange 43 that was flexed last to recover itsoriginal shape before the flange 41 that was flexed first can recoverits original shape. This serves to ensure that the notch 59 is returnedto the lip section 51'.

It has been found that by fixing at least one of the two flanges 41 and43 to the spool core 23 during unwinding rotation of the film spool 5,as contrasted with allowing the flange to remain rotatable independentlyof the spool core as in commonly assigned U.S. Pat. Nos. 4,834,306 and4,848,693, there is immediately effected a frictional relationshipbetween the film leader (outermost convolution) 35 and the skirtedperiphery of the flange which improves the ability of the film spool tothrust the film leader through the light tight passageway 25 to theexterior of the cassette shell 3. In particular, the frictionalrelationship increases the pushing force the spool core 23 will apply tothe film leader 35 to propel the leader out of the cassette shell 3.Moreover, it has been found that by allowing both of the flanges 41 and43 to be rotated independently of the spool core 23 during windingrotation of the film spool 5, as in commonly assigned U.S. Pat. Nos.4,834,306 and 4,848,693, it is substantially ensured that the leader canbe rewound within the skirted peripheries 49 and 51 of the flangeswithout being obstructed by the skirted peripheries.

The invention has been described with reference to a preferredembodiment. However, it will be appreciated that variations andmodifications can be effected within the ordinary skill in the artwithout departing from the scope of the invention. For example, therelieved edge portion 55" of the leader's longitudinal edge 55 could beextended to the leader's forward edge 63. On the other hand, a notchlike the notch 59 could be cut in the leader's longitudinal edge 53.

I claim:
 1. A film cassette comprising (a) a spool core supported forrotation in a film unwinding direction to thrust a leader section of afilm roll coiled about said spool core to the exterior of said cassetteand in a film winding direction to return said leader to the exterior ofthe cassette, and (b) a pair of flanges arranged in spaced relationalong said spool core to radially confine the leader and constructed offlexible material to allow them to be flexed apart to permit the leaderto readily escape the confinement of the flanges when the spool core isrotated in the unwinding direction, is characterized in that:said leaderhas respective edge means for flexing said flanges apart one after theother, rather than simultaneously, when said spool core is rotated inthe unwinding direction, whereby said leader can more easily overcomeany resistance said flanges may present to movement of the leaderoutwardly of the flanges.
 2. A film cassette comprising (a) a spool coresupported for rotation in a film unwinding direction to thrust a leadersection of a film roll coiled about said spool core to the exterior ofsaid cassette and in a film winding direction to return said leader tothe interior of the cassette, and (b) a pair of flanges arranged inspaced relation along said spool core to overlie opposite longitudinaledges of said leader to radially confine the leader within respectiveskirted peripheries of said flanges and constructed of flexible materialto allow them to be flexed farther apart at said skirted peripheries topermit the leader to readily escape the confinement of the flanges whenthe spool core is rotated in the unwinding direction, is characterizedin that:said leader has first and second edge means located one forwardof the other along the respective longitudinal edges of the leader,normally inwardly of said skirted peripheries, for flexing said flangesfarther apart at the skirted peripheries in succession when said spoolcore is rotated in the unwinding direction, whereby said leader can moreeasily overcome any resistance said flanges may present to movement ofthe leader outwardly of said skirted peripheries.
 3. A film cassette asrecited in claim 2, wherein said leader has a forward edge inclinedcloser to said first edge means than to said second edge means.
 4. Afilm cassette as recited in claim 2, wherein said leader has an elongatecut-out at the longitudinal edge of the leader that includes said secondedge means located opposite said first edge means forward of the secondedge means, and the skirted periphery of the flange that the second edgemeans flexes is normally received in said elongate cut-out to permit acorresponding portion of the leader between the elongate cut-out and thefirst edge means to be moved outwardly of said skirted periphery beforethe second edge means flexes the skirted periphery.
 5. A film cassetteas recited in claim 4, wherein said leader has a forward edge, and saidelongate cut-out is sufficiently spaced from said forward edge to allowan intermediate edge portion of the longitudinal edge that includes saidsecond edge means to overlap the skirted periphery normally received inthe elongate cut-out outwardly of said skirted periphery.
 6. A filmcassette as recited in claim 4, wherein said leader has a forward edge,and said elongate cut-out is sufficiently spaced from said forward edgeto allow the forward edge to be thrust substantially to the exterior ofsaid cassette before said second edge means flexes the skirted peripherynormally received in the elongate cut-out.
 7. A film cassette as recitedin claim 2, wherein said flanges are sufficiently resilient to recovertheir original shape, and said leader has respective edge portions ofits opposite longitudinal edges located one forward of the other aheadof said first and second edge means which are relieved to allow theflange that is flexed last to recover its original shape initially andthe flange that is flexed initially to recover its original shape lastwhen the leader is returned to the interior of said cassette.
 8. A filmcassette as recited in claim 7, wherein said leader has a forward edgeinclined closer to said relieved edge portion located ahead of saidfirst edge means than to said relieved edge portion located ahead ofsaid second edge means.